hi, i have a radeon 9600 128 meg... and when im running games it suddenly says that the graphics card is not responding. I have tried re-installing the drivers...but this does not help. Anyone think of anything else i can try????

Which card did you have prior to the ATI. If it was NVIDIA then most likely you still have some remnants of the old drivers. Get a program like Detonator Destroyer to completely remove the old drivers.
Is your card overclocked? If so, take the core and frequency memory down a notch.